Engine starter



NOV. 8, J F TZ E LD 2,136,046

' ENGINE STARTER Filed May 15, 1937 2 Sheets-Sheet l I Non/mu 72 I J.

\N R C: .jmilousa/ Jain K FzfzGEFa/d Nov. 8, 1938. I I J. w. FITZ GERALD 2,136,046

ENGINE STARTER Filed May 15, 1937 2 Sheets-Sheet 2 Q, iv/z/Q v Jahn WHZZGQFE/ Wi ma Patented Nov; s, 1938 ENGINE STARTER mil w. Fitz Gerald, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application May 15, 1937, Serial No. 142,787

This invention relates to improvements in engine starters and refers particularly to starters for automobile engines.

Heretofore, many different types of starters have been proposed, but in general they 'all embodied some form of screw which, upon initial operation of the starter device, effected engagement between the starter pinion and the ring gear of the engine. With this generally accepted design, there was always the possibility of thepinion engaging the ring gear with the teeth meeting end to end, and at all times the shock incidental to picking up the load of the engine had to be ,contended with.

16 To meet these contingencies, good design required both endwise and torsional yieldability. In starters now generally in use, this yieldability, if provided, was obtained through theuse of a spring or springs, and while this construction af- 20- forded the desired yieldability,-the possibilities of breakage and its comparative noisiness were ob- V jectionable.

With these and other objections to past and existing types of engine starters in mind, this in- 25 vention has as one of its objects to provide an improved construction for engine starters which entirely obviates the use of springs and at the same time has all of the required resiliency.

Another object of this invention is to provide 30 an engine starter which is considerably more quiet in operation than those heretofore in use.

More specifically it is an object of this invention to provide an engine starter ,so constructed that a rubber cushion may be employed in place of the 36 spring or springs heretofore used.

' Another object of this invention is to so construct an engine starter of the character described that the rubber cushion is placed in compression in the same direction to afford both endwise and 40 torsional resiliency.

A further object of this invention is to provide .ar engine starter of simpler and less expensive design and construction. i

With the above andother objects in view which 45 will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood 50 that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims. a

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed in accordance with the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a view partly in side elevation and partly in longitudinal section, of an engine starter constructed in accordance with this invention; 5 Figure 2 is a view similar to Figure 1, but showing the manner in which endwise yieldability is obtained; a

Figure 3 is a' view similar to Figure l, illustrating the manner in which torsional yieldability is 10 obtained;

Figure 4 is a perspective view of the nut member;

Figure 5 is a perspective view of the stop member or abutment which cooperates with the-nut member;

Figure 6 is a'perspective view of the rubber cushion which is interposed between the nut member and the abutment; and

Figure 1 is a cross sectional view taken through Figure v1 on the plane of the line 1-1.

Referring now particularly to the accompanying drawings in which like numerals indicate like parts throughout the several views, the numeral 5 designates the ring gear of an engine to be started, and the numeral 6 represents the starting motor. The motor 6 has its shaft I extended past the ring gear to mount a pinion 8 which is I automatically moved into mesh with the ring gear upon initial operation of the starting motor and disengaged therefrom when the engine starts.

The pinion 8 is freely rotatably and slidably mounted on the shaft 1, and has a sleeve 9 extending longitudinally therefrom. The outer end of the sleeve 9 is provided with threads "I which engage the threads ll of a nut member The nut member l2 has an annular flange l3 and two diametrically opposed driving, lugs" H on its outer end. These lugs H are of a size to be slidably received in the spaces between two driving lugs l5 formed on a collar-like abutment or stop member It. This member i6 has a flange ll similar to the flange l3 of the nut member, and is rigidly secured to the outer end of the shaft in any suitable manner, as by a set screw i8.

The interengagmg lugs M and i5 provide a nonrotatable but freely slidable driving connection between the nut member and the stop or abutment l6, and inasmuch as the stop member or abutment is fixed to the shaft,a' driving connection is established between the shaft and the nut member.

Confined between the flanges I3 and I! of the nut member and the abutment, respectively, is a ring-like rubber cushion l9, its bore 20 being of a 5 1 to the shaft in any suitable shown in Figure 1, and the pinion is retracted, the nut member and the collar-like stop member or Operation the parts in their positions illustrated re 1 conjunction with tween the screw Ill and the threads of the'nut member.

II the pinion should end, as depicted in the nut member with respect to the screw causes the nut member to climb out climb out on the threads of the screw to compress the cushion ring. The compression potential energy operating device.

What I claim as my invention is:

The stop 23 is fixed ring encircling said parts and yieldingly opposing endwise movement of saidmembers toward each other.

2. In an engine starter of the character described: a motor driven shaft; a pinion slidable and rotatable on the shaft; means for causing the pinion to move endwise along the shaft including a member having a threaded connection with the pinion; another member fixed with respect to the shaft, said members having slidably but non-rotatably engaged parts; and a ring encircling 1y opposing endwise movement of said members toward each other.

3. In an engine starter of the character described: a shaft; 2. member fixed to the shaft; a screw freely rotatable and slidable on the shaft; a nut slidably but non-rotatably engaged parts; and a cushioning ring encircling said parts and confined between said members.

4. In an engine starter of the character described: a motor driven shaft; a pinion'freely slidable and rotatable on the shaft; a sleeve; a threaded connection between the pinion and ,sleeve adapted upon relative rotation between the pinion and sleeve to impart endwise motion from one of said elements to the other; another sleeve fixed to the shaft, said sleeves having slidably but non-rotatably engaged parts providing a driv- V opposeendwise movement thereof toward each other- 5. In an engine starter of the character described: a motor driven shaft;

member and collar; and compressible means interposed between the nut member and collar and said parts for yielding-- encircling their interengaged parts for yieldingly on the collar similar to that of the nut member; opposing endwise movement of the nut member slidably but non-rotatably engaged parts carand collar toward each other. ried by the nut member and collar between their '7. In an engine starter of the character deflanges to provide a sliding driving connection scribed: a motor driven shaft; a pinion freely between the shaft and nut member; and a rubber 5 slidable and rotatable on the shaft and having an ring encircling said parts and confined between externally threaded portion; a nut member havthe flanges for yieldingly opposing endwise moveing threaded engagement with said portion of mer t of the nut member toward the collar.

the pinion; an annular flange on the nut mem- 10 her; a collar fixed to the shaft; an annular flange JOHN W. FITZ GERALD. 10 

